The present applicant and The Australian National University are the proprietors of a series of inventions in this field. Australian patent application No. AU-B65176/80 (now Pat. No. 531,250) describes a hot uniaxial pressing process including embodiments in which a canister having a generally cylindrical wall of bellows like formation is used to contain the supply material to be pressed and while heating is maintained pressure is applied by a hydraulic press. The synthetic rock product is formed as the bellows like canister is axially compressed.
A further patent application no. AU-72825/82 (now U.S. Pat. No. 524,883) describes a development of the hot uniaxial pressing in which the pressing is conducted in an upward direction against a fixed top abutment in the press.
The prior art referred to in the above specifications includes prior art of The Australian National University describing the formation of synthetic rock from selected phases and suitable for the immobilisation of radioactive waste.
Typically, synthetic rock precursor is in the form of a fine powder and high-level radioactive waste is a liquid which must be impregnated into the powder in the active cell and pressing must also take place in an active cell. Extremely reliable mechanical handling methods and equipment are required since it is desired for the equipment to operate for tens of years with servicing and repairs conducted only through remote manipulators.